Welcome, gravy. I'm so sorry you're going through this. You shouldn't have to live in pain everyday.
I know first-hand that an ostomy would help you, because I got an ileostomy due to having Crohn's disease in my rectum. I started out with a temporary one, and then made it permanent by having my rectum removed.
Life without butt pain is SO much better, and I wish that for you. Have you seen a colorectal surgeon yet? They would be the ones who would do the surgery for you.
Keep us posted!
Dx'd Crohn's in '99 at age 28. Proctocolectomy and permanent ileostomy in '06.
Disease-free and medicine-free since surgery and very thankful to be healthy again.